Symptoms differentiating chikungunya from dengue in children clarified
MedWire News: A combination of fever, high white blood cell (WBC) count, and skin rash during fever in children effectively differentiates chikungunya from dengue virus and other acute febrile illnesses, suggest findings from a Thai study.
Both chikungunya and dengue virus are passed on to humans by Aedes mosquitoes and patients present with similar symptoms, resulting in a high risk for misdiagnosis and inappropriate treatment.
For example, if a patient with dengue hemorrhagic fever is wrongly diagnosed with chikungunya and treated with a nonsteroidal anti-inflammatory drug (NSAID) to relieve symptoms of fever or arthralgia, severe bleeding could occur as a result.
To try and clarify symptoms or combinations of symptoms that are specifically associated with chikungunya over dengue and other illnesses, Kamolwish Laoprasopwattana (Prince of Songkla University, Hat Yai) and colleagues recruited 50 consecutive patients, aged 1 month to 15 years, suspected of having chikungunya. The children were from a chikungunya outbreak area in southern Thailand.
Of the children suspected of having chikungunya, 32 were confirmed as having chikungunya, 10 had dengue virus alone, one had chikungunya and dengue, and seven had another acute febrile illness.
Fever and arthralgia are commonly used to diagnose chikungunya, but Laoprasopwattana and colleagues found that the specificity and positive predictive value of this combination of symptoms for correctly diagnosing chikungunya was only 47.1% and 74.2%, respectively.
A combination of fever, arthralgia, and rash produced a better result of 70.6% and 83.3%, respectively, but a combination of fever for 2 days or less, having a skin rash during fever, and a WBC count of 5000 cells/mm3 produced the best result with a positive predictive value and specificity of 100%.
Writing in the Pediatric Infectious Diseases Journal, the researchers say "a clinical diagnosis of chikungunya based only on fever, arthralgia and/or rash could lead to overdiagnosis of this disease."
They advise that "in areas known to be endemic for dengue, when dealing with children during a chikungunya outbreak who have no skin rash during fever, or a low WBC count, the physician should not forget to include dengue in the differential diagnosis, and should not prescribe any treatment before definite diagnosis that would be contraindicated for dengue, such as an NSAID."
By Helen Albert